Genome-wide Identification And Expression Profiling Of The Sucrose Synthase(SUS) In Capsicum

Sucrose synthase(SUS)is one of the key enzymes in plant sucrose metabolism,and plays crucial role in plant growth,development and resistance to stress.Although the sucrose synthase gene has been studied in many crops in terms of evolutionary origin,expression regulation and stress response,the sucrose synthase family of pepper,as an important vegetable crop,is still poorly understood.With the completion of the whole gene sequencing of pepper,the relevant information of the sucrose synthase gene of pepper is fully understood,which provides an opportunity to further explore and identify the sucrose synthase gene at the genome-wide level.Based on the published data of five pepper genomes,this study used information biology methods to identify pepper sucrose synthase gene family members,and analyzed their chromosomal location,protein conserved motif,phylogenetic relationship,different tissues and developmental stages,different hormones and stress treatments expression patterns.The results of the study are as following:1.Identification and feature analysis of SUS gene family members in pepper.The results showed that total of 25 SUS proteins were encoded by 5 pepper genomes,and each pepper species encoded 5 members.The length of the encode amino acids was between 787?972 aa,the isoelectric point ranged from 5.85 to 8.26,and the molecular weight was 87.96?110.27 k D.Chromosomal localization found that five SUS genes(Capanasus1?Capanasus5)were distributed on four chromosomes.Among these genes,Capanasus3 and Capanasus5 were located on chromosome 3.The length of the 20 conserved motifs(motif 1-20)varied from 6 amino acids to 50 amino acids.2.The evolutionary pattern of SUS gene family in pepper was explored.The phylogenetic tree divided SUS genes into three different groups(SUS??SUS?),which was consistent with the classification of model plant Arabidopsis.Evolutionary analysis revealed differences among different subfamilies of SUS,suggesting that SUS may have different evolutionary patterns.3.Tissue-specific expression analysis of SUS gene in pepper.The study analysis showed that that two SUS genes(Capanasus1 and Capanasus2)were highly expressed in flower,peel and seed development,while the expression level in leaves was low,and the remaining three genes(Capanasus3,Capanasus4 and Capanasus5)in all these tissue that tested(flowers,peels,seeds,and placenta)had low or no expression during development.4.Expression of SUS genes in pepper under various adversity was analyzed.To further explore whether SUS gene is induced by environmental stress,we analyzed the expression patterns of SUS gene under various hormones and abiotic stress.The results show that three SUS genes(Capanasus1,Capanasus2 and Capanasus3)were induced by various hormones(ABA,GA,IAA and JA),while the remaining Capanasus4 and Capanasus5 genes were almost no change.In addition,three SUS genes(Capanasus1,Capanasus2 and Capanasus3)were significantly differentially expressed under stress treatment,while there was no significant change in Capanasus4 and Capanasus5.These results provide a scientific basis for further inquiry into the function of SUS genes in peppers.